A one-year follow-up analysis of a landmark clinical trial suggests that patients with severe strokes experienced better long-term outcomes after undergoing endovascular thrombectomy compared with medical management alone, according to findings published in JAMA.
The study evaluated ischemic stroke patients presenting with large-core infarcts, meaning a significant amount of brain tissue had suffered damage. These patients are historically considered less likely to benefit from mechanical clot removal because of the amount of brain damage that has already occurred by the time treatment begins, said Sameer A. Ansari, MD, PhD, professor and chief of Interventional Neuroradiology in the Department of Radiology, who was a co-author of the study.
While the original trial did not show meaningful benefit at 90 days, the newly reported one-year data show functional gains among patients who received thrombectomy. The results of the current study suggest longer-term follow-up was needed to fully understand the benefits of the procedure, Ansari said.
“At one year, it’s quite evident based on the statistical analysis that there’s significant benefit with thrombectomy,” said Ansari, also a professor in the Ken and Ruth Davee Department of Neurology and of Neurological Surgery.
In the study, investigators found that 23.6 percent of patients treated with endovascular thrombectomy achieved functional independence one year after their stroke, compared with 6.8 percent of patients who received medical management. Patients in the thrombectomy group were also significantly more likely to regain the ability to walk independently, with 35.4 percent achieving independent walking versus 18 percent in the medical-management group.
The multicenter trial enrolled patients at 47 U.S. stroke centers who presented within 24 hours of symptom onset and had large strokes identified using noncontrast computed tomography (CT) imaging.
Patients who underwent thrombectomy also reported better quality of life one year after stroke, while one-year mortality rates were similar between the treatment groups.
The findings add to growing evidence from other large core interventional stroke trials that patients with extensive brain injury can still benefit from rapid thrombectomy to restore blood flow.
One possible explanation for the delayed benefit, Ansari said, is that recovery from severe stroke continues long after the standard 90-day assessment period used in most clinical trials.
“We know that people continue to improve after a stroke for the next one to two years,” Ansari said. “Three months has been an arbitrary standard used in prior stroke trials to assess benefit and functional outcomes after targeted interventions.”
Restoring blood flow may also support long-term neuroplasticity, the brain’s ability to reorganize and form new neural connections after injury, Ansari said. The study reported that patients who received thrombectomy continued to improve between 90 days and one year, while outcomes remained static or declined in the medical-management group.
While more research is needed to fully understand which large core stroke patients benefit most from thrombectomy, the results of the study may provide additional confidence that aggressive intervention can yield meaningful recovery for patients, even when improvement is not immediately apparent.
“What we’re seeing across multiple randomized controlled trials, endovascular thrombectomy remains a powerful intervention across a spectrum of stroke presentations,” Ansari said. “It gives clinicians more confidence to treat patients even with severe brain injury and to counsel their loved ones that the outcome benefit may require time to heal, hard work with physical therapy/rehabilitation, and family support.”
The study was supported by unrestricted grants from Medtronic, Cerenovus, Penumbra, Stryker and Genentech.
